Plasma stage Vs. absolute zero?

I know that when an atom reachs the plasma stage its electrons have gone through diffrent orbitals getting consecutivly larger.

I have a question about what happens as an atom approches absolute zero. as the atom gets colder do its electrons move into smaller orbitals untill they crash into the nuculus or is there an orbital at which they stop?

At ordinary temperatures, you are looking at thermal energies measured in meV; energies necessary to move atoms/molecules from ground electronic states to excited states are measured in eV. Bottom line, "the orbital at which they stop" is called the "ground electronic state," it is reached when systems reach temperatures less than, oh what, let's say 1000 K, and there is no lower electronic state.

When cooling an atomic/molecular system from very high temperatures, the electronic ground state is the first to be reached, from that point you are reducing the translational, rotational, and vibrational quantum numbers to their ground state as you approach 0 K.